Novartis International AG said on Friday that its Sandoz division is abandoning an effort to gain U.S. regulatory approval for a biosimilar of rituximab, a medication used to treat certain cancer and rheumatoid arthritis.

The decision comes after the U.S. Food and Drug Administration (FDA) sought additional information to support the company’s application for the drug, which is approved already in the EU, Switzerland, Japan and Australia, the company said in a statement.

“We are disappointed to have to make this decision and stand behind the safety, efficacy and quality of our medicine,” said Stefan Hendriks, global head of biopharmaceuticals at Sandoz.

Rituximab is a biosimilar drug referencing a Roche Holding AG medication marketed as Rituxan in the United States, Japan and Canada and as MabThera elsewhere. According to analysts, Rituxan, a monoclonal antibody used in non-Hodgkin’s lymphoma and rheumatoid arthritis, had more than $4 billion in sales in the United States in 2016.

A biosimilar is a biologic drug that is virtually identical to the reference product.

An FDA committee in October recommended approval of Truxima, another biosimilar for rituximab, from South Korea’s Celltrion Inc and Israel’s Teva Pharmaceutical Industries Ltd. Approval is expected in late November or December.

Sandoz said it is committed to a robust biosimilar portfolio. It has seven approved biosimilars worldwide, three of which are approved in the United States.

Sandoz received a complete response letter from the U.S. FDA – a communication that tells a company that its application cannot be approved in its current form – for biosimilar rituximab on May 2.